Tengen Toppa Gurren Lagann takes place in a fictional far future where human beings have been forced underground and thrive in isolated subterranean civilizations. These "villages" have no contact with the surface world nor other villages. Since frequent earthquakes damage infrastructure, the villages must constantly expand deeper into the earth — individuals designated to this task are known as "diggers". Jiiha Village is the home of Simon, a fourteen year old digger who was orphaned when his parents were killed in an earthquake. He is respected by the village elder as the best of the diggers, but is ostracized by his peers. After discovering a special drill key deep in the ground, he is recruited by an eccentric fellow orphan named Kamina into his group, the "Gurren Brigade". Kamina dreams of the surface world, which he visited as a child with his father but had to return home because he was too weak to survive.
(taken and edited from wiki)

Picture	Real Name	Description
	Simon	Simon is a fourteen year old digger from Jiiha village. Although he is initially looked down because of it, Simon excels at drilling the earth, while the drill itself quickly becomes his trademark symbol. One day he finds a mysterious drill-shaped item, which is later revealed to be the key for a head-shaped robot he also finds buried in the soil. With the help of the robot, Kamina, and Yoko, he fights off a Gunmen who broke into the village. While finishing the Gunmen off with a drill-like attack, they reach the surface world.
	Kamina	Kamina is a young man from Jiiha village who dreams of leaving the village and go to the surface, which he saw as a kid. He's very passionate about his goals, expressing his wishes through energetic speeches, which seems to affect all those who hear him. He convinces Simon to help him with his plan to drill through the roof of the village and get to the world above, but the plan failed and he was put in prison. He left the village shortly thereafter with the help of Simon and a young girl named Yoko, as a result of fighting a Gunmen, who broke into the village from the surface.
	Yoko	Yoko is a girl from Jiiha's neighboring village Ritona, who had been chasing the Gunmen which entered Jiiha village. She wields an extensive range of firearms and has previous experience fighting Gunmen. She uses her marksmanship from afar to assist Kamina and Simon, while they pilot their gunmens. Although she is said to be around the same age as Simon, she is mature and one of the most rational of the group.
	Nia	Nia is a mysterious young girl found sleeping in a capsule in the middle of a dump site by Simon. She has had no prior contact with humans except her father. She is very curious, pure and innocent, because of growing up sheltered in a peaceful environment, away from all the battles occurring in the outside world. During her travels with the Gurren Brigade, she discovers the harsh reality of the world and develops a strong empathy towards Simon.